My rear window washer, on my '95 850 Estate, was not spraying, and hasn't for at least 3 years. I finally tackled the job.

Thanks to everyone who contributed to the archives on the subject of the rear window washer and the washer system as a whole. I found complete diagrams and discussions on the entire system.

It's a fairly simple system. The front and rear tubes each have a filtering device on them and a pressure relief valve. If the pressure relief valve is leaking out of the top... or spraying... it's bad. The front pump is attached to the reservoir (which is removed from the front under the bumper) and the rear pump is mounted right next to the reservoir. They make noticeably different sounds.

Tracking the front lines is much more complicated than tracking the rear system. That little pump pushes it that entire way. It indeed changes from the rubber hosing that is used everywhere else to a very small plastic line. It's easy to find and follow... looked good on mine. Which is expected, most of the system is connected to the ends of the main line... great engineering, easy to work with.

Tested my pumps (car off, key on option III), hitting the front spray and rear. All good there, still nothing out of the back. Opened the back door and pulled up the right side carpeted panel near the taillight area. There was the other white filter device. Pulled it out and out came a mess of red chunky liquid. Ran some water through it and tons of rusty-looking particles came out in a desert clay colored red liquid. Gross. (Filter itself perhaps went rusty? And corroded?)

Flushed all the lines with washer fluid, bit by bit, connecting and reconnecting areas until all the red stuff was out of the lines.

Couldn't find a replacement filter, but did find an inline fuel filter for a lawn mower... perfect hookups for $3.50... it's clear so I can see the blue window washer flow through it.

I removed the bad pressure relief valve and just put a straight inline connector temporarily on it (couldn't find a connector with a valve... gotta check the dealer I guess.) I suppose i'll go back in there and replace that... or maybe I won't. Anyone know if you have to have a pressure relief valve thing?

Mission accomplished! Rear window washer spraying ever so gloriously again!

 

Thanks! I have the same problem so I will fallow your advice and get it working again


Thanks again,
Chet

 

Nice to see you got everything working. Mine did not work on my 850 but I was just to lazy to tackle the job.

 

Yes, I have been avoiding this job for YEARS! I always thought... "geez, the washer system, it could be something clogged, broken, it could even be the pump"... but after I got in there, I realized that with the way this is designed... you check the pump first (if it's making a sound then it's probably good), and then 2nd check the back filter, the back pressure valve, and then maybe the spray nozzle itself. I mean afterall, how would a clog really even get into that system? (Not saying it's impossible... just more likely to be one of the other several, more obvious, solutions.)

Check...

1. That rear filter (and while you're at it, check the front too)... it might be corroding... not that you can even open them and inspect. But they are $4 parts ordered online... might just be a good replacement if you're unsure.

2. Pressure relief connection (located in the rear right pillar... pull the speaker cover back there and you'll see the line... remove the one screw on the top trim covering that whole area and the rest are just snaps... unsnap it and you'll see the entire line running up along the side.

 

The only thing I could find on the internet about that valve was that it's called the "washer check valve" and here's what it looks like...

http://www.carpartsdiscount.com/auto...tml?3593=75963

Sure, there's the funny looking one in the front, but the rear uses a different style (because it's not being split off)... and it looks just like this one...

The other side of this picture would be rounded with the hole in it. Either way, good price and you'll be prepared when you need it.

 

Does it matter which way you orient the tee check valve. The new one I ordered doesn't have any markings on it, but I would think it would be directional.

 

It should be directional. Try blowing or sucking lightly in each direction and you should be able to figure it out.